1. The Field of the Invention
The present disclosure relates to image display systems, and more particularly, but not necessarily entirely, to image display systems that form images on non-planar surfaces.
2. Description of Background Art
With recent advances in technology, curved projection screens, such as those in planetariums and other “domed theaters,” have seen a resurgence in popularity among viewers. Large curved projection screens are typically formed on the inner surface of a spherical or hemispherical dome, such as those found in planetariums. In some instances, curved projection screens may be many times larger than a conventional theater screen and may provide a sensation to the audience members that they are experiencing the images in real life.
One drawback to the use of curved projection screens is the inability to show images created for conventional “flat” movie screens without objectionable distortions. In particular, displaying a rectangular image on a curved surface, e.g., a curved projection screen, causes the image to be distorted as the center of the image appears to bulge outward towards the audience, while the outer edges of the image appear to bend away. In this case, the center of the image appears disproportionately large, while the outer edges appear disproportionately small and compacted. Thus, in the past, planetariums have generally been unable to show images intended for viewing on a conventional movie screen. Instead, planetariums have been limited to shows particularly created for viewing on curved projection screens.
Some solutions have been employed to show rectangular images on a curved projection screen. One previously available solution for displaying a rectangular image on a curved surface is to use a specially adapted projector with a fisheye lens. For example, IMAX Corporation has developed a motion-picture format that involves filming through a fisheye lens and projecting through the same type of fisheye lens onto a curved screen or projecting a rectangular image through a fisheye lens onto a curved screen. One drawback, however, to this type of solution is the need for specialized equipment for both capturing the image and projecting the image.
In addition, currently available video compositing software can distort rectangular pre-rendered digital images to conform to a curved projection screen. However, the “distorted” images must remain relatively small in comparison to the overall size of a curved projection screen. If for example, the “distorted” image is projected on more than one quarter of a dome, the distortion becomes extremely objectionable. Moreover, the existing video compositing software does not adequately compensate for the complexity of a three-dimensional shape and the curvature of a dome surface.
The features and advantages of the present disclosure will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by the practice of the disclosure without undue experimentation. The features and advantages of the disclosure may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims.